The correlation length divergence of Tolman's length

The curvature dependence of the surface tension of liquid drops is studied. A closed expression is derived for the first curvature correction, δ (Tolman's length) to the surface tension. From this expression, we show that when phase interchange symmetry is absent, δ(1) vanishes identically if the density profile is sharp (a step function), (2) is nonzero otherwise, and (3) diverges as the correlation length. It is also shown that the curvature dependence of the surface tension for a finite-sized drop in an Ising model cannot be extracted from the flat interface.